Method for slitting tapes and displacing adhesive



Feb. 4, 1958 2,822,286

METHOD FOR SLITTING TAPES AND DISPLACING ADHESIVE v c. w. VOGT Filed Sept. 21, .1953

FIG.5

FIG.6

INVEN TOR.

CLARENCE W- VOGT ATTORN EYS;

METHOD FOR SLITTING TAPES AND DISPLACING ADHESIVE Clarence W. Vogt, Norwalk, Conn.

Application September 21, 1953, Serial No. 381,286

4 Claims. (Cl. 117-4) The present invention relates to methods and apparatus for slitting bands of adhesively coated material and forming the same into rolls of adhesive tape, as well as to the resulting products formed thereby.

More particularly, the invention relates to methods and apparatus (as well as products) by means of which bands of adhesively coated material may be slit and simultaneously formed in such fashion that the marginal portions of the adhesive material will be modified in such fashion as to provide rolls of adhesive tape, the edges of the convolutions of which lie in common parallel planes that are perpendicular to the axis of the roll and wherein the edges or sides of the roll are clean and not fouled with escaping adhesive material.

It is a matter of common knowledge that pressure sensitive adhesive tapes now commonly available have the disagreeable property, particularly in the Summertime, of becoming fouled at the sides of the rolls by reason of the fact that the pressure sensitive adhesive escapes from between the convolutions of the roll and is present upon the sides thereof. In order to overcome these and other objections, the present invention has been made and, in order that it may be more fully understood, reference will now be made to the accompanying drawings, wherein:

Fig. 1 is a view in side elevation showing an apparatus in somewhat schematic form and by means of which the present invention may be practiced;

Fig. 2 is an enlarged view somewhat in perspective and partially in section taken on the plane indicated by the line 2-2 of Fig. 1 and looking in the direction of the arrows;

Fig. 3 is a partial plan view of a portion of the band of tape material, illustrating the structure thereof in the region of the band where its cutting or slitting is accomplished (the line 3-3 in Fig. 1 illustrates the region of the tape illustrated in Fig. 3);

Fig. 4 is a partial view in section similar to Fig. 2, and showing a modified form of the invention;

Fig. 5 is a partial view in section showing a portion of a roll of adhesive tape formed in accordance with the present invention; and

Fig. 6 is a view in side elevation showing a roll of adhesive tape formed in accordance with this invention.

Turning to the above drawings, a roll of tape material is illustrated at 10, this material either having had an adhesive coating applied to one side thereof or, if desired, it may be uncoated material to which adhesive material is applied by means of a coating device C as the material is drawn from the roll. in any event, tape material from the roll 10 is illustrated at 11 and passes over guide rollers 12 and 13 and between heating elements 14, and 16 by means of which the band of material, as well as the adhesive coating applied thereto, may be heated to a desired extent. The heating elements have shutters 14', 15' and 16', which may be adjusted to regulate the heating of the web or closed to shield the web from the heating elements when the web stops.

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The tape material may be plain or it may be printed with suitable decorative or other matter before or after being withdrawn from the roll 10.

The adhesively coated material then moves over a heated back-up roll 17, in association with which one or more conventional score-slitting rolls 18 may be provided. Score-slitting rolls are commonly used for slitting paper webs and the like and are usually blunt, rounded edge disks which sever or slit the paper or the like principally by pressure. As illustrated, the score-slitting rolls 18 are mounted upon a suitable retracting mechanism 19 in order that they may be withdrawn from slitting relation with respect to the back-up roll 17. The structure is such that the adhesive side of the band of material 11 is in contact with the back-up roll 17 and the slitting rollers 18 are thus applied to the uncoated or back side of the band of material 11.

In Fig. 2 the adhesive coating is illustrated at 20 and the score slitters are shown as two in number. The sides of the slitters taper away from the blunt slitting edge and thus cause a varying pressure to be applied to the regions of the band of material 11 adjacent the line of cut. As a result, the band of material is indented, as illustrated at 21, 22, 23 and 24 in Fig. 2. The pressure thus applied to the portions 21, 22, 23 and 24 squeezes the adhesive and results in a gradually diminishing thickness of adhesive material as the precise line of cut is approached at the edges of the slits formed in the band of material 11. These marginal regions of diminishing thickness are illustrated respectively at 25, 26, 27 and 28.

Some of the adhesive material in the marginal regions 25, 26, 27 and 28 is transferred to or offset upon the heated back-up roller 17, such portions being indicated generally by the stippled portions 29 in Fig. 2 so that the tape directly beneath the slitter is free of adhesive. A suitable heated doctor 30 may be provided to scrape such portions of adhesive from the back-up roller 17, or these portions may be removed or destroyed in any other suitable fashion. Unless the roll 17 is heated, the adhesive will not transfer to the roll and a clean, adhesive-free edge is not produced at each side of the slit. The heated roll 17 as well as the heater element 14- is also useful for drying ink which may be imprinted on the web to ornament or mark it immediately before slitting the band. Printing and slitting at almost the same time assures proper positioning of the printed matter with respect to the edges of the strips severed from the band of material 11.

The adhesive layer on the band of material 11 and adjacent the region of the cuts formed therein is illustrated in Fig. 3, reference characters 31 and 32 indicating the slits formed by the respective score slitters 18, and the marginal bands of reduced thickness of adhesive are illustrated by the absence of stippling.

Following the slitting operation, the strips of adhesive material are passed over a guide roller 33 and directed to a plurality of wind-up rollers 34 and 35 in order that a. plurality of rolls of adhesive tape 36 (Fig. 6) may be formed. The roll 33 may be cooled to reduce the temperature of the tape. The structure of the roll 36 is illustrated in Fig. 5 wherein it will be seen that the thickness of the adhesive 20 on the respective convolutions of tape material is gradually reduced as the edges of the tape are approached. As a result, any tendency of the adhesive material to seep or escape from between the convolutions will merely result in the material occupying a portion of the void spaces between the convolutions of the roll, and none will escape beyond the sides of the roll.

In Fig. 4, a modified form of slitting mechanism is illustrated. in this structure, a score slitter 37 is provided having a zigzag or pinking profile. The sides of the slitter taper away from the line of cut and, as above described, cause the adhesive material to be removed from the marginal edges of the tape to provide the advantage hereinabove mentioned. Moreover, removal of the adhesive along the zigzag .or pin ked edges permits the adhes ive coated tape to be unrolled withoutbreaking at the roots of the pinks.

It is understood, of course, that the temperature of the adhesive should reach its highest points when and where it is caused to be pressed into intimate contact with heated roll 17, and directly under the noses of each of the score slitters 18. In the spaces intermediate the score slitters, where there is substantially no pressure to cause intimate contact of the adhesive with the back-up roll, the heat transfer is of a substantially lower order. It is also desirable, under certain conditions, to accomplish the slitting operation by means of substantially tangential contact of the tape material with the rollers 17 and 18. As illustrated in Fig. 1, the normal path of the tape material may be somewhat spaced from the back-up roller 17 in order that no overheating or offsetting or transfer of adhesive material may take place during down periods of the machine.

It has also been found that, under certain conditions, a somewhat higher back-up roll temperature is desirable in order to accomplish the transfer of the adhesive to the back-up roll adjacent the slitters. This is particularly true because of a mere tangential or momentary contact of the web ,With the back-up roll. In this connection it has been found that with tape materials having adhesives of the kind used on Scotch type of pressure sensitive tapes, desirable transfer of adhesive occurs at temperatures in the range of about 220 to 250 F. These temperatures depend, of course, upon the nature of the tape and the adhesive material. For example, microcrystalline wax coatings soften and also transfer at substantially lower temperatures than the above.

This invention relates generally to the subject matter described in my copending applications Serial Nos. 285,335, now abandoned, and 335,536, filed April 30, 1952, and February 6, 1953, respectively.

I claim:

1. The method of forming rolls of adhesive tape comprising applying a coating of adhesive material to a base material, drawing the coated material forward by contact with a drive member, moving the coated material over a heated supporting surface with the adhesively coated surface in contact with the supporting surface, applying a score cutting element to the uncoated surface of the base material .to sever the material into a plurality of portions and transfer adhesive from the severed edges of said portions to said supporting surface, and subsequently rolling the severed portions of the material into a plurality of rolls of adhesive tape.

2. The method of claim 1 wherein the cutting of the base material is accomplished with simultaneous application of pressure to the uncoated surface of the base material in a band adjacent the severed edge.

3. The method of claim 1 wherein the cutting of the base material is accomplished by forming the severed edge with a multiplicity .of reversely extending portions.

4. The method of claim 1 wherein, simultaneously with he cutting of the base material, pressure is applied to the ,uncoated siuface adjacent the line of cut and diminishing inwardly of the line of cut.

References Cited in the file of this patent UNITED STATES PATENTS 1,834,998 Becker Dec. 8, 1931 1,978,631 Herr-linger Oct. 30, 1934 2,089,312 Topping Aug. 10, 1937 2,106,133 Goldman Ian. 18, 1938 2,152,012 Albion Mar. 28, 1939 2,293,178 Stocker Aug. 18, 1942 2,340,127 Karl-son Jan. 25, 1944 2,343,720 Van Norde Mar. 7, 1944 2,384,657 Tyler Sept. 11, 1945 2,510,120 Leander June 6, 1950 2,596,400 Hill May 13, 1952 

1. THE METHOD OF FORMING ROLLS OF ADHESIVE TAPE COMPRISING APPLYING A COATING OF ADHESIVE MATERIAL TO A BASE MATERIAL, DRAWING THE COATED MATERIAL OVER A WITH A DRIVE MEMBER, MOVING THE COATED MATERIAL OVER A HEATED SUPPORTING SURFACE WITH THE ADHESIVELY COATED SURFACE IN CONTACT WITH THE SUPPORTING SURFACE, APPLYING A SCORE CUTTING ELEMENT TO THE UNCOATED SURFACE OF THE BASE MATERIAL TO SEVER THE MATERIAL INTO A PLURALITY OF PORTIONS AND TRANSFER ADHESIVE FORM THE SEVERED EDGES OF SAID PORTIONS TO SAID SUPPORTING SURFACE, AND SUBSEQUENTLY ROLLING THE SEVERED PORTIONS OF THE MATERIAL INTO A PLURALITY OF ROLLS OF ADHESIVE TAPE. 